How to clean a dishwasher: a monthly four-week routine

How to clean a dishwasher properly is one of those jobs that feels like it needs a Sunday afternoon, so most Glasgow households put it off until the inside smells like a damp dishcloth. We do not. The ScrubClub team splits the work across four short sessions, one a week, so nothing ever gets bad enough to need a heroic effort. This is the routine we teach every new team member, with the dwell times we use on regular cleans in the West End and Southside.

The four sessions are: week one, the filter and sump. Week two, the spray-arms. Week three, the door seal and detergent dispenser. Week four, a hot empty cycle with vinegar to lift limescale, which Glasgow's moderately hard water does deposit even if you do not see it. Each session takes ten to twenty minutes. By the end of the month the machine is fully serviced and you start again.

What is the best thing to clean a dishwasher with?

For routine monthly cleaning, the best thing is white vinegar plus warm soapy water and a soft brush. White vinegar (the cheap 5 percent stuff from any Glasgow supermarket) handles limescale and biofilm, warm soapy water handles the greasy food residue around the filter and door seal, and a soft-bristled brush like an old toothbrush gets into the spray-arm holes and the seal folds.

Branded dishwasher cleaner sachets (Finish, Bosch, etc.) are useful as an occasional booster, maybe once a quarter, but they are not a substitute for actually opening the machine and cleaning the filter by hand. Most of the smell people blame on the cleaner not working is just trapped food in the filter mesh. No tablet can wash that out from the outside.

What we avoid: bleach (damages stainless steel interiors over time and reacts badly with any rinse-aid residue), and abrasive scourers (scratch the plastic spray-arms and the door panel). The same stainless-steel caution applies to pans, where our four-method burnt pan test found the gentlest soak beat the most aggressive scrub. Bicarbonate of soda is fine on the door rim but pointless inside the wash chamber, the alkaline rinse will undo whatever the vinegar just dissolved if you mix them on the same cycle.

How to clean a dishwasher filter?

Pull the bottom rack out, twist the cylindrical filter anti-clockwise to lift it free, and rinse it under a hot tap with washing-up liquid and a soft brush. This is week one's job, it takes about ten minutes, the filter sits in the sump at the back-centre of the dishwasher floor on almost every machine built since 2010, and if yours twists out in two parts (a fine mesh inside a plastic frame), separate them and clean both.

1. Run the most recent cycle so the chamber is empty, then let it cool for ten minutes.
2. Pull the lower rack fully out and set it on a worktop.
3. Locate the filter at the back-centre of the floor. Twist the top anti-clockwise (usually a quarter turn) until it lifts free.
4. If there is a separate coarse filter (a flat plastic grid) and fine mesh, separate them.
5. Rinse both under a hot tap. Use a small brush on the mesh until water flows through cleanly. Old food, especially rice and oats, embeds in the mesh and is the single biggest cause of dishwasher smell.
6. Wipe out the sump (the little well the filter sat in) with a damp cloth. Fish out anything solid: olive stones, bits of label from jars, the occasional teaspoon.
7. Drop the filter back in, twist clockwise until it locks, and refit the rack.

Do this monthly if you run the machine four or five times a week. Weekly if you run it daily, or if anyone in the house cooks a lot of rice or porridge.

What is the best way to clean the inside of a dishwasher?

The best way is to clean the parts that actually trap residue, in this order: filter, spray-arms, door seal, detergent dispenser, then run an empty hot cycle with vinegar. Wiping the visible interior walls is mostly cosmetic, the smell, the cloudy glasses and the gritty residue all come from those four components, not the walls.

Spray-arms (week two) lift off without tools on most machines. The lower one usually pulls straight up; the upper one twists off via a central nut you turn by hand. Hold each one up to the light and look at the holes. If any are blocked, a wooden cocktail stick or a paperclip clears them. Rinse under a hot tap, refit, and spin them by hand to confirm they turn freely.

The door seal (week three) is where black mould most often appears in Glasgow tenement kitchens, especially the bottom curve where water pools. A cloth dipped in warm soapy water, run all the way around the rubber gasket including the underside lip, takes about five minutes. The detergent dispenser flap also gets a sticky build-up of old tablet residue, that wipes off with the same cloth.

How to give a dishwasher a deep clean?

For a proper deep clean, do all four weekly sessions in one go and finish with a hot empty cycle using one cup of white vinegar in a dishwasher-safe mug on the top rack. Set the cycle to the hottest programme available (usually 65 to 70 degrees, often labelled Intensive or Pots and Pans), and the whole job takes about an hour of hands-on time plus the cycle running.

1. Empty the machine. Pull both racks out.
2. Remove and clean the filter as above.
3. Remove both spray-arms, clear the holes, rinse and refit.
4. Wipe the door seal all the way round, including the underside.
5. Wipe the detergent dispenser flap and the salt cap (if your machine has one, top it up while you are there).
6. Wipe the door panel and the inside of the door, the bit you only see when it is open.
7. Place a heatproof mug holding 240ml of white vinegar upright on the top rack. Do not pour vinegar straight into the base, it dilutes too fast and can corrode the rubber sump seal over time.
8. Run the hottest empty cycle.
9. Once finished, leave the door ajar for an hour to dry the chamber fully.

We do this version on the changeover deep clean for short-let kitchens, where the previous tenant has left the dishwasher in an unknown state. For a regular family home, the spread-it-over-four-weeks version is gentler on your time and gets you the same result.

What happens if you put vinegar and baking soda in the dishwasher?

If you put them in together on the same cycle, they neutralise each other and you get fizz, then nothing. The vinegar (acid) and baking soda (alkali) react to form water, salt and carbon dioxide, the fizzing looks dramatic but the cleaning power of both is gone within seconds, so do not run them together.

What does work is sequential: vinegar on a hot cycle to lift limescale and grease, then a separate short cycle with a small handful of baking soda sprinkled on the floor of the chamber to deodorise and brighten the stainless steel. We rarely bother with the baking soda step. If the filter and seals are clean, the machine does not smell, and the brightener in modern dishwasher tablets handles staining.

How do you stop dishwasher smell coming back?

You stop it by clearing the filter monthly, scraping plates before loading (not full plate-rinsing, just the obvious solids), and leaving the door ajar for an hour after every cycle so the chamber dries. Smell is biofilm, which needs warm, damp, food-rich conditions to grow, so remove any one of those three and it cannot establish.

Glasgow's water is moderately hard, which means limescale builds slowly on the heating element and inside the spray-arms. Limescale itself does not smell, but it gives biofilm a rough surface to cling to. The monthly vinegar cycle keeps it in check. If your machine has a salt reservoir, keep it topped up with dishwasher salt (not table salt), it feeds the built-in water softener and dramatically reduces scale on the heater.

How often should I deep clean my dishwasher?

Run the four-week routine every month if you use the dishwasher daily, every six weeks if you run it three or four times a week, and once a quarter if it is more occasional than that. The single best indicator is the filter: lift it out and look, and if you can see embedded food in the mesh, you are overdue.

On homes with pets, especially dogs that lick plates before they go in, we shorten the interval. Pet hair binds with grease in the filter mesh and forms a paste that is much harder to rinse out than ordinary food residue.

That same logic, slightly different routine, applies to the rest of the kitchen.Our kitchen deep clean order walks through which surfaces get done in which sequence, and why.

What about hard water marks on the inside of the door?

Cloudy white marks on the inside of the door panel are limescale, and the easiest fix is a cloth dampened with neat white vinegar held against the marks for two minutes, then wiped off. The dwell time is what matters: a quick wipe will not touch them, two full minutes of contact dissolves them, and rinsing the cloth with clean water afterwards stops the vinegar smell lingering.

For stubborn cases, especially in older Bearsden and Newton Mearns kitchens where the dishwasher has been on the same hard-water supply for a decade, we use a slightly stronger 50:50 mix of white vinegar and warm water in a spray bottle, mist the door, leave it five minutes, then wipe. Never use limescale removers designed for kettles or bathrooms inside the dishwasher, they are far too aggressive for the rubber and plastic components.

For the other appliance that needs the most thought in a Glasgow kitchen,oven cleaning, DIY or specialist covers when to do it yourself and when it is genuinely worth booking out.

When should I just book a deep clean instead?

If the machine has not been opened up in over a year, if there is visible black mould around the seal, or if the smell persists after a full filter and spray-arm clean, the dishwasher is part of a wider kitchen problem and a single deep session of the kitchen, including under and behind the appliance, will reset it faster than another round of vinegar cycles.

That is what a one-off deep clean is built for. The team pulls the dishwasher out, cleans the floor and walls behind it, services the machine itself, and puts it back. About four hours for a typical Glasgow kitchen.

Eight years cleaning Glasgow tenements, short lets and family homes has taught us that the dishwasher is almost always the appliance that gets neglected longest, simply because it is hidden behind a door. The four-week routine fixes that. The same staged approach applies to other forgotten fixtures, including the radiator dust pass we run before winter. If you would rather we just sorted it, the team is the same Glasgow crew we have had since 2019, fully insured, and you can see what local customers think on our Google profile.

Want us to fold the dishwasher service into a regular visit?Get a quote in 60 seconds and we will build it into the rota.